Rock drill



Sept. 22, 1925. 1,554,777

L. c. BAYLES ET AL nocx DRILL Filed llay 29, 1923 INVENTOR lieu/1; ahafl les fl 1 5 edM la en HIS ATT NEY Patented Sept. 22, 1925.

,umreo STATES PATENT OFFICE.

i 1 LEWIS c. BAYLnsAnn FRED M, SLATER, or EAsron,'.-rrinNsY Iivirnii ,assienons 'ro INGEB-SOLL-RAND COMPANY, or JEB-SEI QITY, N JERSEY, A oonroaa'rion on NEW JERSEYQ V BOOK DRILL.

Applioati-onfile d May 29,1923. se ia-no.eaawai I To aZZ whom it may concern:

Be it known that we, Lewis G. BAYLESI. and FRED SLATER, citizens. of the United (States, and residents of Easton, county of (Northampton and a Pennsylvania,

hays invented a certainRock Drill, of whichf. the! following is a specification, accoma paniedbyfldrawing.

" motive fluid is prevented from entering the hollow drill. steel along with the water used for cleansing the holes in the rock, thus pre-i I venting fogging andthecreation of fine'h I p V another spacer Z may be insertedbetween dust inthe atmosphere. A further object is to change the present existing machines of .the. hammer type, so as to prevent the delivery of motive fluid to the drill steel along 1 y chuck key V, and chuck front bushing Y with the cleansingwater.

ure is a longitudinal sectional elevation, of so much of a rock drill of the type known as the Leyner, as will serve to illustrate the invention.

Referring to the drawings, the cylinder A is provided with a main bore B and the forward bore C of smaller diameter, which latter bore may be formed by a cylinder front washer D either separate from or integ'ra-l with the cylinder. A piston E, adapted to reciprocate in the cylinder is provided with a forward extension F fitting the bore C of smaller diameter. A hollow drill steel (it is carried in the usual manner by the forward end of the machine, and extends into the machine to a position to receive the impact blows of the piston. A water tube H extends longitudinally through and approximately fits a hole in the piston and is adapted to deliver water to the drill steel.

Motive fluid is supplied to the machine through the inlet J controlled by a suitable throttle valve, of which the controlling handle X only is indicated. A suitable fluid distributing valve may be provided in the valve chest L, but as the distribution of motive fluid to the cylinder forms no part of the present invention, the details of such construction are not indicated. The piston is provided with a rifle bar nut O cooperating with the rifle bar P and the usual back head is indicated at Q, having the water Thisinvention relatesto alfluid actuated M rock drill ofthe hammer. type, and its ob-' the chuck "connection R. The parts of the machine are helditogether by the usual side bolts S, a

portion of one side bolt only being shown;

Any suitable and u sual front head, construction for the machine may beprovided, I 1nv this instance, so much ofthestandard Leynerconstructionheing shown as may used with our im mvemeat: The front head T is provided with tliefront head cap U, in'which is located thechuck key vfi' The chuck nut'Wisthreadedto the chuck and within the chuck are located the chuck front bushingYand the chuck backbushserted betiveen'the bushings Yand Z and back bushing Z and the chuck nut W. .7 1 o so far described, the front head capfU,

and chuck nutW'are all standard parts, but in accordance witlr'our inventionthe piston extension F is made somewhat longer and the flutes a are located on the rearward portion only of the extension, or that por tion of the piston extension which enters the main bore B. The flutes begin at points (0 adjacent the piston head and extend for wardly for a portion of the length of the piston extension, terminating at the points Z). The remainder of the piston extension having a smooth and preferably unbroken surface 0 forms a seal with the chuck back bushing Z, so that communication between the main bore B and the chuck cavity (Z adjacent the rearward end of the drill steel is constantly sealed and motive fluid is prevented from blowing through the flutes a into the front head parts ofthe machine. Although the flutes a are permitted to free- 1y enter the main bore of the cylinder, air is prevented from passing down through the hollow drill steel from the main bore, owing to the substantial seal provided be tween the smooth cylindrical surface of the piston extension, and the chuck back bushing Z.

Any motive fluid which may leak past the seal around the smooth portion of the piston extension or pass around the water tube H through the hole in the piston, will escape to atmosphere from the space at surrounding the extreme shank end of the drill steel, because of the loose fit of the drill steel shank in the chuck front bushing Y. This also prevents the accumulation of pressure in the said space or chuck cavity 03.

Qbv el he 9 Pa t o mproved du'stless piston and front end constructi'on may be constructed in different Ways, without departing from the spirit of the invention. The attached drawing shows the invention applied tothepresent standard Leyner machine, the only alterations beingthe use of a piston having a longer forward ext ens-ionv with the flutes at the rearward portion ofthe extension instead of on the forward portion as heretofore, and such changesin the chuck parts as may be necessaryto accommodate the new type of piston, Obviouslyalso, the chuck back bushing Z and the spacing pieces Z and Y. need not all be separate pieces. Itwill' also be seen that the forward smooth portion of the pistonextension is of smaller diameter than the outside diameter otthe fluted portion.

y In practice clearance left between the,

flutes a and the flutesofv the nut W for the reason that the machining of theflutes and nut and the alignment of thepiston E in the cylinder, the joint between the front head T and cylinder A, need not beabsolutely accurate. There is therefore a slight turning of the piston E. with respect 'to the chuck X. A corresponding turn also occurs between the washer or chuck back bushing Z and the nose 0 which is per- 7 mitted without leakage therebetween since the! surfaces of the two latter parts are accurately cylindrical. The washer Z being of metal or an unyielding material does not bind on the piston nose 0 whether the pistonvE is rotating or reciprocating. The seal effected thereby is for this reason durable and effective.

'WVe claim v In a fluid actuated rock drilhthe combination of a cylinder having a main bore, a forward bore of smaller diameter, a front head, a chuck rotatable in the front head for receiving the dri-llsteel, a nut in the chuck, a piston in the cylinder having a fluted for- Ward extension cooperating With the nut in the chuck, a smooth cylindrical metal Washer in the chuck forward of ,the nut and a smooth cylindrical portion for-med integrally with the piston extension forward of the fluted portion free to rotate in the washer with respect tothe washer and to "reciprocate without binding therew vithin to prevent motive fluid from passing from the cylinder beyond said washer. g In testimony whereof we have signed this specification. 1

- LEWIS C. BiAYLES. FRED 'M. SLATER. 

